as long as you already have everyhting mic-ed, have you thought of renting, or borrowing an Alesis HD24?
If your FOH board has direct outs, you could use them. Otherwise, you could use the inserts-to-the-first-click thing.
Once you have the tracks, you transfer them to a PC, and with some trial and error, and some descent monitors, and multi-tracking software, you could get some very good recordings.
I've recorded my band like that for years, and have gotten some amazing recordings. (do a search in the mp3 mixing forum on my screen name (or Beatles) for some examples).
I've had studio owners claim I'm a fraud for the clarity and quality of some of the mixes I've done. But I assure you, everything was one-take, right off the stage recordings.
